The present invention relates to a flat panel display device, and more particular to an electron supplying device of the flat panel display device having a magnetic plate supplying the uniform magnetic field to holes thereof to form an electron beam to be impacted to the screen.
The cathode ray tube (CRT) used for the display device such as television and personal computer, etc., has problem that the size is increased in accordance with the display area. In order to overcome this problem the flat panel display including a liquid crystal display device, a field emission display device, a plasma display panel device, and a vacuum fluorescent display device has been introduced recently. Since these flat panel display device requires the high level technology such as the semiconductor device process, however, the manufacturing process is complex and the cost is increased. In case of the fabrication of the large size device, further, there are problem such as the image quality deterioration and the color shift phenomenon.
It is an object of the present invention to provide a magnetic plate having a first region including a plurality of holes in which the magnetic field is applied and a second region formed in the outer peripheral portion of the first region to apply the uniform magnetic field into the holes all over the first region of the magnetic plate.
It is another object of the present invention to provide an electron supplying device for focusing the electrons to be flowing into the holes to generate an electron beam.
It is another object of the present invention to provide a flat panel display device in which the electron beam generated by the magnet of the magnetic plate is impacted into a screen to display the image.
In order to achieve the object, the magnetic plate according to one aspect of the present invention comprises a first region having a plurality of holes for focusing the electron inputted from the outside of the magnetic plate by the magnetic field to generate the electron beam; and a second region formed in the outer peripheral portion of the first region to supply the uniform magnetic field to the holes all over the first region.
The holes of the circular shape or the rectangular shape in the first region are arranged in a plurality of rows and columns at uniform pitch. In the second region, further, a plurality of holes is also arranged in the same shape and pitch as the first region.
The electron supplying device according to the other aspect of the present invention comprises a cathode for emitting the electrons; a magnetic plate having a first region and a second region, the first region including a plurality of holes for focusing the electrons emitted from the cathode to generate the electron beam by the magnetic field, the holes being arranged in two dimension matrix, the second region being formed in the outer peripheral portion of the first region to apply the uniform magnetic field into the holes all over the first region; a grid electrode for controlling the flow of the electrons flowing into the holes of the magnetic plate, the grid electrode being positioned between the cathode and the magnetic plate, and first and second anodes for accelerating the electrons flowing into the holes, the first and second anodes being arranged parallel along both sides of the columns of the holes in the surface of the magnetic plate that do not face the cathode.
The holes of the circular shape or the rectangular shape are arranged in a plurality of rows and columns at uniform pitch in the first region. In the second region, further, a plurality of holes is arranged in the same shape and pitch as the first region. The grid electrodes are arranged in matrix on the surface of the cathode or the surface of the magnetic plate facing to the cathode, and the holes are formed at the intersection of the grid electrodes. The grid electrodes and the anodes are formed in only the first region, but could be extended to the second region. The first and second anodes are electrically connected to the neighboring the first and second anodes, respectively.
The flat panel display device according to the another aspect of the present invention comprises a cathode for emitting the electrons; a magnetic plate having a first region and a second region, the first region including a plurality of holes for focusing the electrons emitted from the cathode to generate the electron beam by the magnetic field, the holes being arranged in a plurality of rows and columns, the second region being formed in the outer peripheral portion of the first region to apply the uniform magnetic field into the holes all over the first region; a plurality grid electrodes for controlling the flow of the electrons flowing into the holes of the magnetic plate, the grid electrodes being formed between the cathode and the magnetic plate; first and second anodes for accelerating the electrons flowing into the holes, the first and second anodes being parallel arranged along both sides of the column of the holes in the surface of the magnetic plate that do not face the cathode; a screen having a fluorescent layer over the surface facing the surface of the magnetic plate on which the anodes are arranged; and a controlling signal supplying means for supplying the controlling signal to the grid electrodes and the anodes to control selectively the stream of the electrons impacted into the fluorescent layer from the cathode.
The holes of circular shape or the rectangular shape are arranged in a plurality of rows and columns at pitch b in the first region and a plurality of holes having the same shape and pitch as the first region are formed in the second region. The grid electrodes are arranged in matrix in the surface of the cathode or the surface of the magnetic plate opposing to the cathode, and the holes are arranged at the intersection of the grid electrodes. The grid electrodes and the anodes are formed in only the first region, but could be extended to the second region. The first and second anodes are electrically connected to the neighboring the first and second anodes, respectively.
The fluorescent layer includes a plurality of red, green, and blue elements to be repeated thereon. The refractive signal is applied to the first and second anodes to refract the electrons flowing out the holes of the magnetic plate, so that the refracted electrons are impacted to each element of the fluorescent layer to generate the image on the screen.
The cathode, the magnetic plate, and the screen spaced in uniform gap by a spacer are sealed and then evacuated. The spacer is smaller than the width of the second region of the magnetic plate, so that the spacer is positioned in a part area or the whole area of the second region.